This invention relates to stub sill underframes for railway tank cars.
Previously, stub sill underframes for railway tank cars have been fabricated by welding together a pair of Z sections to form a channel and then burning out an opening to receive a curved tank car cradle pad to reinforce the tank. In addition, in the burned out area, reinforcing gussets extending vertically between the stub sill flanges and the top of the stub sill are provided.
Welding the Z sections together, burning out the opening and welding in place the horizontal reinforcements are timeconsuming and expensive operations.
In another construction disclosed in U.S. Pat. No. 3,308,769, the horizontal portion of the channel is formed into a concave shape and a cradle pad is welded to the upper surface of this concave surface.